use correct context to cancel list and watch & wait for all informers to complete

Signed-off-by: Tim Ramlot <[email protected]>

Author: inteon

pkg/cache/internal/informers_map.go

@@ -117,9 +117,6 @@ type InformersMap struct {
 	// paramCodec is used by list and watch
 	paramCodec runtime.ParameterCodec
 
-	// stop is the stop channel to stop informers
-	stop <-chan struct{}
-
 	// resync is the base frequency the informers are resynced
 	// a 10 percent jitter will be added to the resync period between informers
 	// so that all informers will not send list requests simultaneously.
@@ -128,13 +125,22 @@ type InformersMap struct {
 	// mu guards access to the map
 	mu sync.RWMutex
 
-	// start is true if the informers have been started
+	// started is true if the informers have been started
 	started bool
 
 	// startWait is a channel that is closed after the
 	// informer has been started.
 	startWait chan struct{}
 
+	// waitGroup is the wait group that is used to wait for all informers to stop
+	waitGroup sync.WaitGroup
+
+	// stopped is true if the informers have been stopped
+	stopped bool
+
+	// ctx is the context to stop informers
+	ctx context.Context
+
 	// namespace is the namespace that all ListWatches are restricted to
 	// default or empty string means all namespaces
 	namespace string
@@ -158,24 +164,42 @@ func (ip *InformersMap) Start(ctx context.Context) error {
 		defer ip.mu.Unlock()
 
 		// Set the stop channel so it can be passed to informers that are added later
-		ip.stop = ctx.Done()
+		ip.ctx = ctx
+
+		ip.waitGroup.Add(len(ip.informers.Structured) + len(ip.informers.Unstructured) + len(ip.informers.Metadata))
 
 		// Start each informer
 		for _, i := range ip.informers.Structured {
-			go i.Informer.Run(ctx.Done())
+			i := i
+			go func() {
+				defer ip.waitGroup.Done()
+				i.Informer.Run(ctx.Done())
+			}()
 		}
 		for _, i := range ip.informers.Unstructured {
-			go i.Informer.Run(ctx.Done())
+			i := i
+			go func() {
+				defer ip.waitGroup.Done()
+				i.Informer.Run(ctx.Done())
+			}()
 		}
 		for _, i := range ip.informers.Metadata {
-			go i.Informer.Run(ctx.Done())
+			i := i
+			go func() {
+				defer ip.waitGroup.Done()
+				i.Informer.Run(ctx.Done())
+			}()
 		}
 
 		// Set started to true so we immediately start any informers added later.
 		ip.started = true
 		close(ip.startWait)
 	}()
-	<-ctx.Done()
+	<-ctx.Done() // Block until the context is done
+	ip.mu.Lock()
+	ip.stopped = true // Set stopped to true so we don't start any new informers
+	ip.mu.Unlock()
+	ip.waitGroup.Wait() // Block until all informers have stopped
 	return nil
 }
 
@@ -260,6 +284,10 @@ func (ip *InformersMap) addInformerToMap(gvk schema.GroupVersionKind, obj runtim
 	ip.mu.Lock()
 	defer ip.mu.Unlock()
 
+	if ip.stopped {
+		return nil, false, fmt.Errorf("cannot add informer to stopped InformersMap (GVK: %v, obj: %T)", gvk, obj)
+	}
+
 	// Check the cache to see if we already have an Informer.  If we do, return the Informer.
 	// This is for the case where 2 routines tried to get the informer when it wasn't in the map
 	// so neither returned early, but the first one created it.
@@ -311,16 +339,16 @@ func (ip *InformersMap) addInformerToMap(gvk schema.GroupVersionKind, obj runtim
 	// TODO(seans): write thorough tests and document what happens here - can you add indexers?
 	// can you add eventhandlers?
 	if ip.started {
-		go i.Informer.Run(ip.stop)
+		ip.waitGroup.Add(1)
+		go func() {
+			defer ip.waitGroup.Done()
+			i.Informer.Run(ip.ctx.Done())
+		}()
 	}
 	return i, ip.started, nil
 }
 
 func (ip *InformersMap) makeListWatcher(gvk schema.GroupVersionKind, obj runtime.Object) (*cache.ListWatch, error) {
-	// TODO(vincepri): Wire the context in here and don't use TODO().
-	// Can we use the context from the Get call?
-	ctx := context.TODO()
-
 	// Kubernetes APIs work against Resources, not GroupVersionKinds.  Map the
 	// groupVersionKind to the Resource API we will use.
 	mapping, err := ip.mapper.RESTMapping(gvk.GroupKind(), gvk.Version)
@@ -351,16 +379,16 @@ func (ip *InformersMap) makeListWatcher(gvk schema.GroupVersionKind, obj runtime
 		return &cache.ListWatch{
 			ListFunc: func(opts metav1.ListOptions) (runtime.Object, error) {
 				if namespace != "" {
-					return resources.Namespace(namespace).List(ctx, opts)
+					return resources.Namespace(namespace).List(ip.ctx, opts)
 				}
-				return resources.List(ctx, opts)
+				return resources.List(ip.ctx, opts)
 			},
 			// Setup the watch function
 			WatchFunc: func(opts metav1.ListOptions) (watch.Interface, error) {
 				if namespace != "" {
-					return resources.Namespace(namespace).Watch(ctx, opts)
+					return resources.Namespace(namespace).Watch(ip.ctx, opts)
 				}
-				return resources.Watch(ctx, opts)
+				return resources.Watch(ip.ctx, opts)
 			},
 		}, nil
 	//
@@ -386,9 +414,9 @@ func (ip *InformersMap) makeListWatcher(gvk schema.GroupVersionKind, obj runtime
 					err  error
 				)
 				if namespace != "" {
-					list, err = resources.Namespace(namespace).List(ctx, opts)
+					list, err = resources.Namespace(namespace).List(ip.ctx, opts)
 				} else {
-					list, err = resources.List(ctx, opts)
+					list, err = resources.List(ip.ctx, opts)
 				}
 				if list != nil {
 					for i := range list.Items {
@@ -400,9 +428,9 @@ func (ip *InformersMap) makeListWatcher(gvk schema.GroupVersionKind, obj runtime
 			// Setup the watch function
 			WatchFunc: func(opts metav1.ListOptions) (watcher watch.Interface, err error) {
 				if namespace != "" {
-					watcher, err = resources.Namespace(namespace).Watch(ctx, opts)
+					watcher, err = resources.Namespace(namespace).Watch(ip.ctx, opts)
 				} else {
-					watcher, err = resources.Watch(ctx, opts)
+					watcher, err = resources.Watch(ip.ctx, opts)
 				}
 				if err != nil {
 					return nil, err
@@ -433,7 +461,7 @@ func (ip *InformersMap) makeListWatcher(gvk schema.GroupVersionKind, obj runtime
 
 				// Create the resulting object, and execute the request.
 				res := listObj.DeepCopyObject()
-				if err := req.Do(ctx).Into(res); err != nil {
+				if err := req.Do(ip.ctx).Into(res); err != nil {
 					return nil, err
 				}
 				return res, nil
@@ -446,7 +474,7 @@ func (ip *InformersMap) makeListWatcher(gvk schema.GroupVersionKind, obj runtime
 					req.Namespace(namespace)
 				}
 				// Call the watch.
-				return req.Watch(ctx)
+				return req.Watch(ip.ctx)
 			},
 		}, nil
 	}